Cap for a container containing a volatile air treatment agent

ABSTRACT

This invention relates to an air treatment device using a volatile treating agent contained inside of a permeable container ( 1 ) and a cap ( 4 ) closing the container ( 1 ). The cap ( 4 ) comprises a reservoir ( 12 ) containing the active agent.

This invention relates to an air treatment device using a volatiletreating agent housed inside of a permeable container, and moreparticularly the cap of such a device.

Such devices are used to ensure the disinfection, sterilisation and/ordeodorisation of air, particularly in heating, ventilation and/orair-conditioning systems, and more particularly the passengercompartment of a vehicle. Its object is a cap for a container containinga volatile air treatment agent, in particular for treating the aircirculating though such a system.

Devices are known for treating air by using a volatile treating agentplaced inside a permeable container, in order to gradually diffuse thetreating agent through the wall of the permeable container over aspecific period of time. This treatment, for example, is a fungicidal,antimicrobial or odorising treatment.

According to a first known solution, the treating agent is a liquidcontained inside a gas-permeable, liquid-impermeable pouch, itselfpackaged inside an impermeable container that is removed at the time thedevice is used. For example, reference may be made to the document U.S.Pat. No. 4,961,493, which discloses such a device.

Conversely, and according to another known solution, the treating agentis a liquid contained inside of an impermeable pouch, itself containedin a permeable container. When the device is used, the impermeable pouchis broken in order to release the treating agent inside the permeablecontainer. For example, reference may be made to the document U.S. Pat.No. 5,458,244, which discloses such a device.

Nevertheless, triggering the diffusion process is difficult, because itrequires multiple handling phases. Moreover, it is necessary to tear apackage containing the active components. This step may result in damageto the device.

A device is also known for treating air with a volatile agent containedinside of a permeable container, which offers a satisfactory, stable andcontinuous diffusion of the treating agent while at the same timeoptimising the surface available for diffusing the treating agentthrough the permeable container in order to ultimately reduce theoverall space requirement thereof.

However, such devices have the disadvantage of not allowing control overthe triggering of the diffusion process. As a matter of fact, thediffusion process becomes operative once the treating agent is insertedinto the permeable container. Thus, prior to being installed in the airtreatment apparatus for which it is intended, the treating agent hasbegun to diffuse through the walls of the permeable container. Theamount of treating agent for final use within an air treatment apparatusis therefore reduced.

Therefore, the purpose of this invention is to solve the previouslydescribed disadvantages. For this purpose, it proposes a cap comprisingan interior wall and a bottom forming a reservoir. Preferentially, theinterior wall is cylindrical.

Furthermore, the reservoir is sealed off from the outside environment byan inner seal. It may therefore contain an active agent.

According to an alternative embodiment, the interior wall and the bottomhave thicknesses defined so as to prevent the treating agent frommigrating towards the exterior of the reservoir.

This invention also proposes an air treatment device using a volatiletreating agent contained inside of a permeable container that is closedby a cap having one of the characteristics specified above.

Thus, an embodiment such as this makes it possible to control thetreatment process triggering phase simply and quickly, since it occursafter insertion of the cap into the permeable container. In addition,this invention makes it possible to store the products without any riskof reducing the treating power of the treating agent.

According to a first additional characteristic of the invention, thereservoir is closed by an inner seal.

According to a second characteristic of the invention, the devicecomprises perforating means making it possible to pierce the inner seal.

According to another embodiment, the device comprises a body forsupporting the treating agent.

Another characteristic of the invention consists of the fact that thepermeable container comprises ribs that clamp tightly around the body.

Alternatively, the cap occupies at least one first and one secondposition in relation to the permeable container.

According to one alternative of the present invention, the permeablecontainer comprises a wall having an interior face including at leastone indexing groove.

It is then preferentially coupled with a boss that is arranged on anexterior wall of the cap and that cooperates with the indexing groovesin order to define various positions of the cap in relation to thepermeable container.

According to another embodiment, the permeable container comprises awall having an interior face including an internal thread thatcooperates with a thread made on an exterior wall of the cap in order toscrew the cap into the permeable container.

Shifting from the first position to the second position is done bytransversely displacing or rotating the cap in relation to the permeablecontainer.

The first position, referred to as the high position, is such that sealof the reservoir is preserved. The second position, referred to as thelow position, is such that the seal of the reservoir is broken.

This invention is such that the seal of the reservoir is broken by theperforating means, which may consist of the body comprising a perforatorat its upper portion and an additional perforator mounted inside thepermeable container.

Ideally, the perforator rests on the ribs of the permeable container.

Other advantages and characteristics of the invention will becomeapparent upon reading the following description. This description ispurely illustrative, is given by way of example, and must be read whilereferring to the appended drawings in which:

FIG. 1 shows an exploded view of a device for treating air with atreating agent according to this invention,

FIGS. 2 and 3 show a sectional view of a closing cap for the device ofthis invention, according to a first embodiment,

FIGS. 4 and 5 show a sectional view of a closing cap for the device ofthis invention, according to a second embodiment,

FIGS. 6 and 7 show a sectional view of a closing cap for the device ofthis invention, according to a third embodiment, and

FIG. 8 shows a top view of the perforator for a closing cap of thedevice of this invention, according to the third embodiment.

Reference is made first to FIG. 1, which shows a device for treating airwith a treating agent.

The device according to this invention is designed for treating air witha volatile treating agent contained inside of a permeable container 1.

According to this invention, the treating agent is preferentially keptin the liquid state, or similarly, in a state in which it is capable ofbeing absorbed by a spongy mass.

The treating agent is packaged by absorption into a spongy body 2serving as a support for the treating agent housed inside the permeablecontainer 1. The body 2 has the characteristic of being spongy whilehaving the property of being able to easily soak up the treating agent.

The body 2 is, in particular, formed from a porous mass arranged like aplug, the volume of which occupies at least partially, e.g., almost all,of the volume of a chamber 6 formed by an internal hollowed-out portionof the permeable container 1.

The body 2 is dry and is introduced into the receiving chamber 6 thatthe permeable container 1 comprises. It is subsequently soaked with atreating agent in the liquid state, in particular allyl isothiocyanate.

Advantageously, the shape of the body 2 is substantially complimentaryto that of the chamber 6, in order to optimise the occupation of theuseful volume of the permeable container 1, with the exception of a thinlayer of air arranged between the body 2 and the wall of the permeablecontainer 1. For this purpose, centring ribs 20 are arranged on theinterior wall of the permeable container 1. The ribs 20 are positionedover a small angular portion. Thus, this arrangement makes it possibleto reduce the overall exterior dimensions of the permeable container 1.Owing to these arrangements, and to the rigid nature of the permeablecontainer 1, its installation is facilitated. In the embodiment exampleshown, the body 2 is shaped like a cylindrical plug. For example, it maybe formed from a textile felt.

The volume of the chamber 6 is substantially equivalent to the volume ofthe body 2. However, a residual space between the body 2 and the lateralwall of the permeable container 1 is created by the ribs 20, in order tohave thin layer of air available for the diffusion process.

After having soaked the body 2 in liquid form, the treating agentchanges into a gas in the residual space between the body 2 and thelateral wall of the permeable container 1. As a result, the diffusionprocess enables gas migration of the treating agent through the lateralwall of the permeable container 1 so that it is released into theoutside environment. The permeable container 1 ensures gradual diffusionof the treating agent over a specific period of time.

The thickness and the surface of the lateral wall of the permeablecontainer 1 are defined so as to ensure optimal diffusion of thetreating agent via migration through the lateral wall.

In particular, a wall thickness ranging between 0.5 mm and 2 mm offersan acceptable compromise for ensuring optimal diffusion. Moreparticularly, for an annual diffusion of 45 mg/day of treating agent, inparticular allyl isothiocyanate, at a constant temperature on the orderof 40° C., it is preferable to have a permeable container 1 thickness ofthe order of 0.9 mm, plus or minus 20%, for an overall surface area of4200 mm², plus or minus 10%.

However, these dimensions are dependant on the surrounding outsideenvironment; more particularly, they are based on the temperature, andthe required intensity of the diffusion process.

The permeable container 1 is equipped with a cap 4 for plugging thechamber 6. According to this invention, the cap 4 comprises a reservoir12 containing the treating agent. In an initial arrangement, thetreating agent is stored in the cap 4 and is separated from the body 2.

As concerns the permeable container 1, it is rigid and is formed from apermeable plastic material, e.g., 20% talc-filled polypropylene.

According to an alternative embodiment, the permeable container 1comprises a protuberance 8 that makes it possible to fasten the airtreatment device onto the filtering medium or peripheral edge by meansof a suitable clamp or clip. It is also possible to fasten the permeablecontainer 1 onto the heating, ventilation and/or air-conditioningapparatus.

FIG. 2 shows a first embodiment according to this invention. Accordingto this arrangement, the cap 4 comprises a reservoir 12 containing thetreating agent. The reservoir 12 contains a sufficient amount oftreating agent to impregnate the body 2 for optimal functioning of theair treatment device.

This reservoir 12 is made by the interior wall 14 and the bottom 16 ofthe cap 4. It thus defines a volume ranging between 2 and 10millilitres. Preferentially, it has a volume of 4.4 millilitres.However, these volumes are capable of being varied in order tocorrespond to the airflow treatment needs, in particular the desiredservice life of the treatment device and the climate surrounding thepermeable container 1.

Preferentially, the interior wall 14 is cylindrical. However, it ispossible to consider providing a reservoir having a different internalgeometry.

The cap 4 is made of plastic, in particular polypropylene. However, thethicknesses of the walls 14 and 16 are defined so that the cap 4 doesnot allow the treating agent to migrate towards the exterior of the cap4.

The reservoir 12 is sealed off from the outside environment by an innerseal 18. Similarly, the inner seal 18 provides a perfect seal betweenthe interior of the reservoir 12 and the outside environment. In thisway, it is ensured that the treating agent is not able to migratetowards the exterior of the cap 4.

Thus made, the cap 4 contains a specific amount of treating agent thatis insulated in a perfectly leak-proof manner from the outsideenvironment. It is therefore possible to store these caps 4 for a longperiod of time without any reduction in the amount of treating agent dueto uncontrolled migration through the walls 14 and 16 or the inner seal18.

Preferentially, the inner seal 18 is a sheet of aluminium that is firmlyfastened onto the interior wall 14 of the cap 4, by gluing or welding,for example. However, the inner seal 18 may be made of a multilayeraluminium film.

In FIG. 2, the device is described in a first position. In thisconfiguration, the cap 4 is inserted into the permeable container 1 inthe high position.

The permeable container 1 comprises a lateral wall 22. According to theembodiment example, the wall 22 is cylindrical. The inside diameter ofthe wall 22 is identical to the outside diameter of the cap 4. Anassembly such as this ensures a perfect fit between the cap 4 and thepermeable container 1. In this way, a perfect seal is made between thecap 4 and the permeable container 1.

On its interior face, the wall 22 comprises indexing grooves 24 and 26.Groove 26 is arranged above groove 24. The distance separating thegrooves 24 and 26 determines the placement of the cap 4 in the highposition and low position respectively.

The indexing grooves 24 and 26 cooperate with a boss 28 arranged on theexterior wall 17 of the cap 4. In high position, the boss 28 cooperateswith the indexing groove 26. In low position, the boss cooperates withthe indexing groove 24. The boss 28 serves as an index that is insertedinto the indexing grooves 24 and 26.

The embodiment described comprises two indexing grooves 24 and 26. Asneeded, particularly in order to provide several intermediate positionsbetween the high position and the low position, it is possible to have alarger number of indexing grooves.

In the same way, in order to simplify the embodiment, it is possible toconsider having a single indexing groove. In this configuration, itindicates either the high position or the low position.

Ribs 20 are also arranged on the internal face of the permeablecontainer 1. They are distributed evenly around the periphery and,ideally, over small angular portions.

The ribs 20 ensure centring of the body 2, so that the latter isperfectly centred inside the permeable container 1. Furthermore, bydistributing the ribs 20 around the periphery, over small angularportions, this arrangement aims to facilitate the insertion of the body2 into the chamber 6 while providing a space between the body 2 and thepermeable container 1. A layer of air occupies this space and promotesthe release of the treating agent by allowing diffusion of the treatingagent.

According to an alternative, these ribs 20 are arranged over a portionof the height of the permeable container 1, and preferentially at theupper portion of the permeable container 1, so as to ensure centring ofthe body 2 in relation to the cap 4 and the reservoir 12.

The body 2 is a dry stabilising material placed inside the chamber 6 ofthe permeable container 1. According to this invention, the stabilisingmaterial is a spongy body, e.g., made of felt. However, it is possiblefor this stabilising material to be a mineral, plant or even animalmaterial.

Additionally, the role of the body 2 is to prohibit direct contactbetween the treating agent, in liquid form, and the lateral wall 22 ofthe permeable container 1. In the opposite case, contact between thetreating agent and the lateral wall 22 would have effects on themigration path of the treating agent through the wall 22, and wouldtherefore alter the diffusion rate of the treating agent.

At its upper portion, the body 2 comprises a perforator 30. According tothe embodiment example, the perforator 30 is made directly from astabilising material. Ideally, it assumes a cone shape.

The role of the perforator 30 is to ensure the opening of the reservoir12 and to release the treating agent when the cap 4 is in the lowposition, by piercing the inner seal 18.

In the arrangement of FIG. 2, the cap 4 is placed on the permeablecontainer 2 in a high position. It corresponds, in particular, to astorage position of the air treatment device prior to its finalinstallation in an air treatment apparatus, such as a heating,ventilation and/or air-conditioning system. In this configuration, theboss 28 cooperates with the indexing groove 26. The reservoir 12 ishermetically sealed by the inner seal 18, because the perforator 30 isdistant from the inner seal 18.

FIG. 3 shows the device in a second position, according to the firstembodiment. In this configuration, the cap 4 is inserted into thepermeable container 1 in the low position.

The low position is the configuration that enables triggering of theprocess of diffusing the treating agent through the opening of the innerseal 18.

In comparison with the high position described in FIG. 2, the cap hasbeen pushed in, specifically by a transverse movement of the cap 4 alongthe axis of the permeable container 1, so that the boss 28 cooperateswith the indexing groove 24.

FIGS. 2 and 3 show the same device in two different positions.Consequently, the elements common to both figures have identicalreferences to those described in relation to FIG. 2.

In this transition phase between the high position and the low position,the distance separating the tip 32 of the perforator 30 and the innerseal 18 gradually decreases. When the tip 32 of the perforator 30 comesinto contact with the inner seal 18, it tears it while creating anopening 34.

The treating agent present in the reservoir 12 sealed by the inner seal18 is released. It then impregnates the body 2 by capillary attractionand is diffused into the stabilising material. In this way, the entirevolume of the body 2 contains the treating agent.

In this position, the opening 34 is at its maximum. The diffusion of thetreating agent is therefore optimal.

The diffusion process is then initiated and the treating agent migratesas a gas through the lateral wall 22 of the permeable container 1, so asto be released into the outside environment.

According to this invention, the perforator 30 is made from thestabilising material of the body 2. The latter is dimensioned to ensureperforation of the inner seal 18. In order to do this, the dimensions,shape, hardness and rigidity are selected for piercing the inner seal 18under known conditions of pressure on the cap 4.

In the embodiment example, the perforator 30 is cone-shaped. However, itis possible to likewise consider giving it a pyramidal shape, acylindrical shape truncated along an inclined plane or an off-centredcone. In addition, depending on the pressure exerted by the perforator30 on the inner seal 18, it is also possible to consider using asmall-diameter cylinder or a parallelepiped having a narrowcross-section.

Henceforth, reference will be made to FIG. 4, which shows a secondembodiment of the device. The embodiment example of FIG. 4 has numeroussimilarities with the previously described embodiments. The elementscommon to both examples are taken up again using similar references.

The device is described here in a first position. In this configuration,the cap 4 is inserted into the permeable container 1 in the highposition.

The embodiment of FIG. 4 differs from that described in FIG. 2 by themanner in which the cap 4 is set into motion. The indexing mechanismcomprising a boss 28 and indexing grooves 24 and 26 is replaced by athread 25.

FIGS. 4 and 5 show the same device as that described in FIGS. 2 and 3,with different means of assembly. Consequently, the common elements inthe figures have identical references to those described in relation toFIGS. 2 and 3.

The exterior wall 17 of the cap 4 is threaded while the interior face ofthe wall 22 is tapped. Thus, the placement of the cap 4 in the permeablecontainer 1 is accomplished by a screw-nut type of assembly.

The high position is therefore defined by a specific number of rotationsof the cap 4, in order to ensure that the assembly engages with aselected number of threads.

The low position is defined in an identical way, by a specific number ofrotations of the cap 4. However, provisions may also be made for the lowposition to be reached when the thread comes to a stop inside theinternal thread.

The thread assembly offers the advantage of being able to moreaccurately define the position of the cap 4 in relation to theperforator 30. Thus, it is possible to control the flow rate of thetreating agent into the body 2. As a matter of fact, depending on themovement of the cap 4, the perforator 30 pierces the inner seal andcreates an opening 34. The treating agent is diffused through theopening 34 into the stabilising material of the body 2. As a result ofthe shape of the perforator 30 and the degree of penetration of the tip32 of the perforator 30, it is possible to have a larger or smalleropening ensuring a greater or lesser diffusion of the treating agentinto the stabilising material of the body 2.

FIG. 5 shows the device according to the second embodiment, in a secondposition. In this configuration, the cap 4 is inserted into thepermeable container 1 in the low position.

In this position, the opening 34 is at its maximum. The diffusion of thetreating agent is therefore optimal.

In the transition phase between the high position and the low position,the distance separating the tip 32 of the perforator 30 and the innerseal 18 gradually decreases. When the tip 32 comes into contact with theinner seal 18, it tears it while creating an opening 34.

The treating agent present in the reservoir 12 sealed by the inner seal18 is released. It then impregnates the body 2 by capillary attractionand is diffused into the stabilising material. In this way, the entirevolume of the body 2 contains the treating agent.

The diffusion process is then initiated and the treating agent migratesas a gas through the interior wall 22 of the cap 4 so as to be releasedinto the outside environment.

According to this invention, the perforator 30 is made from thestabilising material of the body 2. The latter is dimensioned to ensureperforation of the inner seal 18. In order to do this, the dimensions,shape, hardness and rigidity are selected for piercing the inner seal 18under known conditions of pressure on the cap 4.

In the embodiment example, the perforator 30 is cone-shaped. However, itis possible to likewise consider giving it a pyramidal shape, acylindrical shape truncated along an inclined plane or an off-centredcone. In addition, depending on the pressure exerted by the perforator30 on the inner seal 18, it is also possible to consider using asmall-diameter cylinder or a parallelepiped having a narrowcross-section.

FIGS. 6 and 7 show a third embodiment of the device in the high positionand low position respectively. The alternative embodiment of FIGS. 6 and7 shows a device very similar to that described in FIGS. 2 and 3 withdifferent perforating means. Consequently, the common elements in thefigures have identical references to those described in relation toFIGS. 2 and 3.

The movement of the cap 4 in this third embodiment may be carried outeither by an indexing device as described in FIGS. 2 and 3, or by athread device as described in FIGS. 4 and 5.

The embodiment of FIG. 6 differs from the preceding embodiments by thedeletion of the upper portion of the body 2 having the function ofperforating the inner seal 18.

As a matter of fact, depending on the stabilising material used, it ispossible that the rigidity of the perforator 30 might not be sufficientto enable it to penetrate into the inner seal 18 and to pierce it.

The alternative embodiment of FIGS. 6 and 7 shows an arrangement inwhich the perforator 40 is an additional part arranged inside of thepermeable container 1.

The perforator 40 is preferentially made of metal, which impartssufficient rigidity thereon to ensure perforation of the inner seal 18.

As shown in FIG. 8, the perforator 40 comprises a ring 38 defining abase from which rise arches 42. The arches 42 support the perforatinghead 44 having a tip 36.

The perforating head 44 also has ribs 46. The ribs 46 serve to createcutting edges on the smooth surface of the perforating head 44. Theirrole is to facilitate separation of the inner seal 18 and theperforating head 44 so that the treating agent flows easily towards thestabilising material of the body 2.

As shown in FIGS. 6 and 7, the base 38 of the perforator 40 rests on thecentring ribs 20 of the permeable container 1. The outside diameter ofthe base 38 is slightly smaller than the inside diameter of thepermeable container 1. This makes it possible to easily insert theperforator into the permeable container 1.

The process of triggering the diffusion of the treating agent isidentical to that described in relation to FIGS. 2 to 5.

The embodiment of FIGS. 6 and 7 provides a broad standardisation of thedevices for treating air with a treating agent. As a matter of fact,such devices may comprise a body 2 pre-impregnated with a treatingagent, which is inserted into the permeable container 1, or else, likethis invention, comprise a “dry” treating agent body 2 and a cap 4containing the treating agent.

Whatever methods are concerned, it is possible to replace and/or refillthe device by the one described above.

As a matter of fact, if the device that one wishes to refill comprises abody 2 pre-impregnated with a treating agent, it is possible to retainthe existing body 2 and to replace the initial cap with a cap accordingto this invention, and to insert an additional perforator like theperforator 40, so as to render the device operative again.

If the device that one wishes to refill comprises a “dry” treating agentbody 2 and a cap with a reservoir of the type of cap 4, it is possibleto retain the existing body 2 and to replace the cap devoid of anytreating agent with a new cap according to this invention, whichcontains an amount of treating agent that ensures prolongation of thetreatment in order to render the device operative again.

According to the embodiments of this invention, the perforating meansconsist of either a particular geometry of the body made of astabilising material, or an additional part inserted between the bodymade of a stabilising material and the cap.

The various examples described enable the cap 4 and the permeablecontainer 1 to be assembled together. This assembly is carried out so asto ensure a perfect fit between the cap 4 and the permeable container 1.In this way, a perfect seal is produced between these two elements.During all of the steps for assembling the cap 4 together with thepermeable container 1, the treating agent, in the liquid state inparticular, is insulated from the outside environment.

As a matter of fact, prior to perforation of the inner seal 18 by theperforating means 30 or 40, the treating agent in liquid form is in thereservoir 12, insulated from the outside environment by the combinationof the inner seal 18 and the interior wall 14 and the bottom 16 whosethicknesses are defined so that they prevent the migration of thetreating agent towards the exterior of the reservoir.

After perforation of the inner seal 18 by the perforating means 30 or40, the treating agent is diffused in liquid form and soaks the body 2.The perfect fit between the cap 4 and the permeable container ensures aperfect seal between these elements and constitutes a guarantee that thetreating agent, in liquid form in particular, is insulated from theoutside environment.

However, those skilled in the art will be able to design the perforatingmeans by any other means that make it possible to pierce the inner sealclosing the reservoir of the cap.

A device such as this is designed, in particular, to be applied to aheating, ventilation and/or air-conditioning system, in particular for amotor vehicle, taking into account the constraints of using andinstalling the device inside such a system, in particular with regard tothe smallest possible overall dimensions desired for the device, thereliability, sustainability and stability of the diffusion of thetreating agent, easy procedures for installing the device inside thesystem as well as procedures for replacing the device, in the case whereit is expendable, or else, in the opposite case, procedures forreplacing the treating agent.

The air treatment device according to this invention is suitable forbeing installed inside of a heating, ventilation and/or air-conditioningapparatus. In particular, for example, it may be fastened onto thefiltering medium of the particulate type, active carbon type, or acombination of the two, for the passenger compartment of a motorvehicle, so as to be arranged in the air flow that circulates throughthe heating, ventilation and/or air-conditioning apparatus, and moreparticularly through the evaporator and the filter. The latter consistsof a peripheral edge or rigid or deformable frame that holds thefiltering medium in pleated form.

The air treatment device may also be fastened onto the peripheral edgeof the filter.

These positions of the air treatment device on a filter, which is itselfinstalled inside a ventilation, heating and/or air-conditioning system,make it possible to destroy the microbes and odours that may developinside of this system.

In a storage phase, this invention thus ensures that the treating agentis kept leak-proof. Furthermore, the body serving as a support for thetreating agent during diffusion is not impregnated. This makes itpossible to preserve the active power of the device over a longer periodof time.

The device according to the invention is suitable for being replacedeach time that the passenger compartment filter of the vehicle ischanged, or for being reused by repositioning it on the new filtermedium or on a wall of the system. This treatment device is thusparticularly suited to use in manufacturers' automobile repair chains orin independent after-sales chains.

This invention also applies to all equipment that involves air flows,the walls and components of which are to be treated.

Quite obviously, the invention is not limited to the previouslydescribed embodiments provided for illustrative purposes only, andencompasses other alternative embodiments that those skilled in the artwill be able to anticipate within the scope of the claims.

1. Cap (4) for a container (1) comprising an interior wall (14) and abottom (16), characterised in that the interior wall (14) and the bottom(16) form a reservoir (12).
 2. Cap of claim 1, characterised in that theinterior wall (14) is cylindrical.
 3. Cap (4) as claimed in claim 1 or2, characterised in that the reservoir (12) is sealed off from theoutside environment by an inner seal (18).
 4. Cap (4) as claimed in oneof claims 1 to 3, characterised in that the reservoir (12) contains atreating agent.
 5. Cap (4) of claim 4, characterised in that theinterior wall (14) and the bottom (16) have thicknesses defined so as toprevent the migration of the treating agent towards the exterior of thereservoir.
 6. Air treatment device using a volatile treating agentcontained inside of a permeable container (1) and a cap (4) closing thecontainer (1), characterised in that the device comprises a cap (4) asclaimed in of the preceding claims.
 7. Air treatment device of claim 6,characterised in that the reservoir (12) is closed by an inner seal(18).
 8. Air treatment device of claim 7, characterised in that thedevice comprises perforating means (30, 40) suitable for piercing theinner seal (18).
 9. Air treatment device as claimed in one of claims 6to 8, characterised in that the device comprises a body (2) forsupporting the treating agent.
 10. Air treatment device of claim 9,characterised in that permeable container (1) comprises ribs (20) thatclamp tightly around the body (2).
 11. Air treatment device as claimedin one of claims 6 to 10, characterised in that the cap (4) occupies atleast a first and a second position in relation to the permeablecontainer (1).
 12. Air treatment device as claimed in one of claims 6 to11, characterised in that the permeable container (1) comprises a wall(22) having in interior face including at least one indexing groove (24,26).
 13. Air treatment device of claim 12, characterised in that the cap(4) comprises an exterior wall (17) including a boss (28) cooperatingwith the indexing groove (24, 26) in order to define various positionsof the cap (4) in relation to the permeable container (1).
 14. Airtreatment device as claimed in one of claims 6 to 11, characterised inthat the permeable container (1) comprises a wall (22) having aninterior face including a internal thread cooperating with a thread madeon an exterior wall (17) of the cap (4), in order to screw the cap (4)into the permeable container (1).
 15. Air treatment device as claimed inone of claims 11 to 13, characterised in that shifting from the firstposition to the second position is done by transversely displacing thecap (4) in relation to the permeable container (1).
 16. Air treatmentdevice of claim 14, characterised in that shifting from the firstposition to the second position is done by rotating the cap (4) inrelation to the permeable container (1).
 17. Air treatment device asclaimed in one of claims 11 to 16, characterised in that the firstposition, referred to as the high position, is such that the seal of thereservoir (12) is preserved, and in that the second position, referredto as the low position, is such that the seal of the reservoir (12) isbroken.
 18. Air treatment device of claim 17, characterised in that theseal of the reservoir (12) is broken by perforating means (30, 40). 19.Air treatment device of claim 17, characterised in that the perforatingmeans are made from the body (2) comprising a perforator (30) at itsupper portion.
 20. Air treatment device of claim 17, characterised inthat the perforating means are made by an additional perforator (40)mounted inside the permeable container (1) .
 21. Air treatment device ofclaim 20, characterised in that the perforator (40) rests on the ribs(20) of the permeable container (1).